title: Three-dimensional ultrasonographic assessments of fetal development.
abstract: OBJECTIVE
  To visualize fetal surface anatomic structures in advancing gestation by use of three-dimensional ultrasonography with a specially developed abdominal three-dimensional transducer.
  
  
  METHODS
  One hundred six normal fetuses from 9 to 40 weeks' gestation were studied with a specially developed abdominal three-dimensional transducer (3.5 MHz). This imaging system can provide conventional two-dimensional ultrasonography images and also can generate within seconds high-quality three-dimensional images in the surface and transparent modes with no need for an external workstation. We determined percentage of surface anatomic structures visualized at each trimester using two-dimensional and three-dimensional ultrasonography.
  
  
  RESULTS
  The number and the clarity of surface anatomic structures increased from the first to the third trimester of pregnancy. The image quality was less distinct in the first trimester because of the small fetal size. The ability to view the fetal face, hands, and feet was better with three-dimensional ultrasonography than with two-dimensional ultrasonography in the first trimester (P < .05), whereas fetal genitals were viewed better with two-dimensional ultrasonography than with three-dimensional ultrasonography in the second and third trimesters (P < .05).
  
  
  CONCLUSIONS
  Three-dimensional ultrasonography provides a new means of visualizing surface anatomic structures of the fetus in utero. Our results suggest that three-dimensional ultrasonography has the potential to be a supplement to two-dimensional ultrasonography and should be useful in evaluating fetal abnormalities in high-risk pregnancies.
authors.affiliation: Department of Obstetrics and Gynecology, Shimane Medical University, Izumo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Hata
authors.forename: S
authors.initials: S
authors.lastname: Aoki
authors.forename: K
authors.initials: K
authors.lastname: Hata
authors.forename: K
authors.initials: K
authors.lastname: Miyazaki
authors.forename: M
authors.initials: M
authors.lastname: Akahane
authors.forename: T
authors.initials: T
authors.lastname: Mochizuki
mesh_terms: D005314:Embryonic and Fetal Development; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D011247:Pregnancy; D016216:Ultrasonography, Prenatal